From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758530Ab0JFBGT (ORCPT ); Tue, 5 Oct 2010 21:06:19 -0400 Received: from mail-iw0-f174.google.com ([209.85.214.174]:35223 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758299Ab0JFBF7 convert rfc822-to-8bit (ORCPT ); Tue, 5 Oct 2010 21:05:59 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:content-type:content-transfer-encoding:subject:date:message-id :cc:to:mime-version:x-mailer; b=iH7firNvCuqBxxvchZ6dxMU+m5W+Ap0rSimIKq2BfLQnfL1qRZ53BFti6wXefqKF5w U5D+fvCmzUQkyQ4vbeX/wD01qN89+KRlN+7pzAvILAykRchbLLDHegQsM1IRF/aokXEg 8KGrbQxN601vpiDBDb3qKKQh8qzBG1wZHXz4s= From: bhs Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Subject: Why not distribute timer handlers on CPUs on SMP Date: Wed, 6 Oct 2010 09:05:52 +0800 Message-Id: <2B624B3F-9338-4336-B4F6-D61B476DA255@gmail.com> Cc: haishan.bai@gmail.com To: linux-kernel@vger.kernel.org Mime-Version: 1.0 (Apple Message framework v1078) X-Mailer: Apple Mail (2.1078) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, I am just curious about why handle the timer functions on a CPU serially but not distribute them over CPUs even on a SMP system? The timer wheel handler function __run_timers() serializes the timer functions on a CPU, is there any design consideration that handling timers on a CPU is more reasonable than distribute them over CPUs? Best regards Shan Hai